When traveling on business or on a vacation, it is very cumbersome to carry the many disparate power adapters for each of the mobile devices. One would rather carry a wireless power pad, if the wireless power pad could charge multiple devices. Such a multi-device charging wireless power pad would certainly be more convenient, however it is an extra piece of luggage that the user would have to remember and carry. It would be even more convenient if mobile devices with big battery capacity such as a notebook, tablet, etc., that typically are carried along on the trips, were able to wirelessly charge other lower battery capacity mobile devices such as a mobile phone, camera, etc., that are also carried on the trips. For example, a notebook's battery capacity would typically be at least 8 times that of a mobile phone's so using the notebook's battery to charge up the mobile phone would not place a heavy drain on the notebook's battery. A mobile device such as notebook, mobile phone, etc., can receive power wirelessly via the wireless power receiver circuitry. To transmit power, the mobile device would need the wireless power transmitter circuitry. It would be ideal if the mobile device's wireless power circuitry could transform into a wireless power receiver or a wireless power transmitter depending on the scenario. In a scenario where the notebook is to be wirelessly charged, its wireless power circuitry should function as a wireless power receiver. In a scenario where the notebook is to wirelessly charge the mobile phone, the notebook's wireless power circuitry should function as a wireless power transmitter.
Consumer electronic device manufacturers are increasingly working on integrating wireless charging and Near field communication (NFC) into a mobile device. In today's implementations, wireless charging and NFC are being packaged together but are completely independent of each other. For example, wireless charging coil with its corresponding impedance matching circuitry in the wireless power receiver is completely independent of that of the NFC antenna and its corresponding impedance matching circuitry. Such a parallel approach is too costly particularly for mobile devices catering to the mid and lower tiers of the market. It would be more economical and space conserving if some of the NFC-like functionality were achieved via the wireless charging circuitry itself so for the cost conscious market, the mobile device manufacturers could eliminate the NFC circuitry and yet deliver a very feature rich device with just wireless charging.
To emulate NFC like functionality, in addition to being able to receive power to charging the mobile device's battery, the wireless power receiver circuitry should also be able to transmit power to perform an action or transaction. The actions and transactions are, for example, unlocking a luggage, unlocking a safe, unlocking a computer, virtual wallet, travel-pass for commuter train, boarding pass for flights, etc. These actions and transactions are better served when security features are built into the hardware of the mobile device. If security features are not built into the hardware of the mobile device, the user is dependent on a software application on the mobile device to offer security features. The software application implementations may or may not offer security features and that could compromise sensitive user information. In addition, a very flexible scheme with varying degrees of authentication and encryption would be needed to allow such actions and transactions.
Hence, there is a need for a dual mode wireless charging receiver with security features built into the hardware of the mobile device that in one mode, receives wireless power to charge, for example, a mobile device, and in another mode, transmits power to a secondary wireless power receiver to perform an action or transaction, where such an action or transaction is made inherently secure and reliable via the two-way communication and security capabilities of the dual mode wireless power receiver and in another mode, transforms into a wireless transmitter for charging a secondary wireless power receiver.